Import AITURK IDE 1.0.0-beta.1 from Hermes 63279301; preserve MIT license

apps/desktop/src/lib/middle-click.test.tsx

@@ -0,0 +1,86 @@
+import { cleanup, fireEvent, render, screen } from '@testing-library/react'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+
+import { middleClickHandlers } from './middle-click'
+
+afterEach(cleanup)
+
+/** A middle click as a real three-button mouse delivers it. Chromium on
+ *  Windows/Linux swallows the trailing `auxclick` when the press starts
+ *  autoscroll, so the gesture may NOT depend on that event. */
+function middleClick(element: Element, upOn: Element = element) {
+  fireEvent.mouseDown(element, { button: 1 })
+  fireEvent.pointerDown(element, { button: 1 })
+  fireEvent.pointerUp(upOn, { button: 1 })
+}
+
+function Target({ action, id = 'target' }: { action?: () => void; id?: string }) {
+  return (
+    <button {...middleClickHandlers(action)} id={id} type="button">
+      {id}
+    </button>
+  )
+}
+
+describe('middleClickHandlers', () => {
+  it('fires without an auxclick — the event Chromium eats when autoscroll starts', () => {
+    const action = vi.fn()
+    render(<Target action={action} />)
+
+    middleClick(screen.getByText('target'))
+    expect(action).toHaveBeenCalledTimes(1)
+  })
+
+  it('cancels mousedown so the autoscroll pan widget never appears', () => {
+    render(<Target action={vi.fn()} />)
+
+    const down = fireEvent.mouseDown(screen.getByText('target'), { button: 1 })
+    expect(down).toBe(false) // preventDefault() called
+  })
+
+  it('cancels the middle mousedown even with no action — the surface owns the button', () => {
+    render(<Target />)
+
+    expect(fireEvent.mouseDown(screen.getByText('target'), { button: 1 })).toBe(false)
+  })
+
+  it('ignores left and right buttons', () => {
+    const action = vi.fn()
+    render(<Target action={action} />)
+
+    const target = screen.getByText('target')
+    fireEvent.pointerDown(target, { button: 0 })
+    fireEvent.pointerUp(target, { button: 0 })
+    fireEvent.pointerDown(target, { button: 2 })
+    fireEvent.pointerUp(target, { button: 2 })
+    expect(action).not.toHaveBeenCalled()
+  })
+
+  it('does nothing when the release lands on a different element', () => {
+    const pressed = vi.fn()
+    const released = vi.fn()
+    render(
+      <>
+        <Target action={pressed} id="pressed" />
+        <Target action={released} id="released" />
+      </>
+    )
+
+    middleClick(screen.getByText('pressed'), screen.getByText('released'))
+    expect(pressed).not.toHaveBeenCalled()
+    expect(released).not.toHaveBeenCalled()
+  })
+
+  it('a press with no action cannot arm the NEXT element it releases over', () => {
+    const action = vi.fn()
+    render(
+      <>
+        <Target id="inert" />
+        <Target action={action} id="live" />
+      </>
+    )
+
+    middleClick(screen.getByText('inert'), screen.getByText('live'))
+    expect(action).not.toHaveBeenCalled()
+  })
+})